Unusual low-temperature magnetization of a cubic Γ3 non-kramers doublet ground state compound prmg ³-evidence of a hybridization effect

Magnetizations of single crystals of cubic PrMg ₃ with a Γ3 non-Kramers doublet ground state have been examined at very low temperatures down to 60mK in magnetic fields up to 8.5 T. No evidence of a long-range order is obtained. Instead, the magnetic susceptibility for both [001] and [111] directions continuously increases on cooling below 3K where the system is well in the Van-Vleck paramagnetic regime, followed by a steep rise due to Pr nuclear Curie law below ̃0:2 K. Subtracting the nuclear contribution from the total magnetization yields a -log T (1 ≤ T ≤ 10 K) or a -√T (0:3 ≤ T ≤ 2:5 K) dependence of the 4f -electronic susceptibility. We argue that a possible random site exchange effect in this Heusler type compound is not the origin of the unusual increase of the susceptibility. Our observations strongly suggest the presence of a hybridization effect between Pr 4f and conduction electrons.